“Rush Plus has been everywhere for the last two-and-a-half months,” he said. “We’ve been working to get the word out and targeting those efforts where the effect of Rush Plus will be felt the greatest, in particular … in places where riders will see colors of trains that today don’t exist.”

According to Metro, during the peak periods of 6:30 a.m. to 9 a.m. and 3:30 p.m. to 6 p.m., six extra trains per hour are being added to the Green and Yellow lines from L’Enfant Plaza to Greenbelt and on the Orange Line between Vienna and Largo Town Center.

Unusual train destinations, like a Yellow Line train destined for Greenbelt, or an Orange Line train headed to Largo Town Center, will result from Rush Plus service changes.

On the Yellow Line, which traditionally has run between Huntington and Fort Totten, riders will be able to travel all the way from Franconia-Springfield to Greenbelt without transferring.

As of Monday, Orange Line riders will be able to go from Vienna to Largo Town Center, a station normally serviced only by the Blue Line.

Riders can expect to see trains more frequently at 21 stations along the Yellow, Green and Orange lines.

Metro estimated that about 110,000 commuters should notice the service improvements. But riders traveling along the Blue Line via Arlington Cemetery could see as much as six extra minutes of wait time during the rush hour because the trains are redirected.

As she made her way out of the Rosslyn station, one of the Blue Line stops that will be affected, Spanish teacher Sadia Manzano said that regardless of the hard work put in by Metro to alert people to prepare for the changes, “It does affect me. I have to get up a little earlier to get to work when I need to.”

Victor Hudson, who lives in Arlington and occasionally leaves for work from one of the Blue Line stops, said he didn’t mind the idea of getting up early if it meant less of a wait on the platform.

“That’s why I was late today,” the car-wash manager said as he made his way to a job interview in Rosslyn. “I saw three trains going the other way. I don’t think [a six-minute delay] is that big a deal.”

Aware there still could be some riders not as well versed in the changes as others, Mr. Stessel suggested that rather than memorizing everything about Rush Plus, “the key is to check the destination on the side of the train or platform displays.”

Joel Volinsky, director for the National Center for Transit Research at the University of South Florida, said a lot of transit systems are making the “very smart decision to reallocate resources.”

“Having trains with different destinations is something that is commonplace on many transit systems,” he said, adding that riders shouldn’t be caught by surprise.

Mr. Stessel said even if there is confusion on Monday, extra Metro personnel are scheduled to be at some of the stations to help riders get where they need to go.